The World
Computer-Bridge Championship is held annually at a major human championship.It has been held at the WBF World
Championships, the American Contract Bridge League (ACBL) North American Bridge
Championships (NABC), and at the first European Bridge Federation (EBL) Open
Championship (2003).Six of the best
robots were entered in this year’s championship, including: the two top past
winners, defending champion Jack (The Netherlands) and WBridge5 (France); past
champions Shark Bridge (Denmark) and Bridge Baron (USA); and many time
runner-ups Q-Plus Bridge (Germany) and Micro Bridge (Japan).

The format
is a 48-board round robin with the two top finishers playing for the Gold medal
in a 64-board KO match, with possibly carryover from the round robin stage.The Conditions of Contest call for a semifinal stage when there are seven
or more entries.Twice before, in
2001 and 2005, were there as few as six robot teams entered.The greatest number of entries was ten, in 2009.

The
contestants all used the same computers, 2.9 GHz Intel Core i5 desktop PCs under
Windows 7 OS.

With one round to
go it was possible for WBridge5, Q-Plus Bridge, Micro Bridge and Jack to take
the two final spots.The standing
after four rounds: WBridge5 (53.26); Q-Plus Bridge (46.51); Jack (45.77); Micro
Bridge (42.37); Shark Bridge (27.43); Bridge Baron (24.66).Interestingly, the new VP scale should eliminate ties. However, if Micro
Bridge beat Jack by 10 IMPs they would tie with 54.07 VPs, but out of the money
as Q-Plus Bridge would have finished second. A
three way tie was almost possible.If
Micro Bridge won by 10 IMPs and Q-Plus Bridge lost by 15 IMPs, Q-Plus Bridge
would have finished with 54.05 VPs. This might show the merits of the new
scale.

Board
5 from the last round robin had the theme...bid one more!

Dealer:
NorthVul: N/S

♠
K Q 10 2♥Q
10 9 7♦8
2
♣ 10 9 2

♠
9 8 5 3♥A♦Q
6 5
♣ K Q 5 4 3

N

W

E

S

♠
A J 7 6 4♥J
5♦9
4
♣ A J 8 7

♠
—♥K
8 6 4 3 2♦A
K J 10 7 3
♣ 6

West

North

East

South

Micro
Bridge

Jack

Micro
Bridge

Jack

Pass

1
♠

3
♣1

4♥

Pass

4
♠

5♥2

5
♠

Dbl

Pass

Pass

Pass

1diamonds
and hearts;2 See Below

The
play started♦K,♦A,♦x,
ruff and over-ruff and now declarer had no trouble in holding the trump losers
to one for down one in 5♠x.
E/W -100.

At
the other table,

West

North

East

South

Jack

Micro
Bridge

Jack

Micro
Bridge

Pass

1
♠

2
♠1

4
♠

Pass

Pass

Pass

1Hearts
and a minor

The
play started♦K,♦A,♦x,
ruff and over-ruff and now declarer had no trouble making 4♠.E/W
+420.

11
IMPs to Jack.

In
another match,

West

North

East

South

Shark
Bridge

Q-Plus
Bridge

Shark
Bridge

Q-Plus
Bridge

Pass

1
♠

3
♣1

4
♠

Pass

Pass

5♥2

Dbl

Pass

Pass

Pass

1Diamonds
and hearts2 See Below

Making
5, N/S +850

West

North

East

South

Q-Plus
Bridge

Shark
Bridge

Q-Plus
Bridge

Shark
Bridge

Pass

Pass

4♥

Dbl

Pass

4
♠

Pass

Pass

Pass

The
play started♦K,♦A,♦x,
ruff and over-ruff and now declarer had no trouble making 4♠,
E/W +420.

15
IMPs to Q-Plus Bridge.

In
the other match,

West

North

East

South

Bridge
Baron

WBridge5

Bridge
Baron

WBridge5

Pass

1
♠

3
♣1

4
♠

Pass

Pass

5♦2

Dbl

5♥

Dbl

Pass

Pass

Pass

1
diamonds and hearts2 See Below

Made
5, N/S +850

West

North

East

South

WBridge5

Bridge
Baron

WBridge5

Bridge
Baron

Pass

1
♠

2♥

4♥1

Pass

4
♠

Pass

Pass

Dbl

Pass

Pass

Pass

The
play started♦K,♦A
and♥4.Now
declarer led a spade to the jack, and had to loss two trumps fordownE/W
-100.

Hans
Kuijf ..."Robots
are certainly less partner oriented than humans. There are many reasons for
that. Most human partnerships demand that. In fact humans tend to invite rather
than bid game themselves just because of that. Even when in fact they have a
hand across which partner cannot possibly make the correct decision. The truth
is somewhere in the middle: Humans include partner too much and robots not that
much. The reason in Jack [5♥bid)
is this: he anticipates a bid, not based on simulations for which we lack the
CPU time, but on a rule base.If
partner is able to make the right decision in a number of samples then Jack
includes him in the bidding (either by inviting or making some other descriptive
bid). In
this case: 5♦ tends to show longer
diamonds than hearts. Humans [South] however will certainly bid 5♣or
4N with equal length)."

Yves
Costel..."WBridge5 has a rule to add one to the length of a long suit
with AKQ or AQJT or AKJT. In that case diamonds are considered longer than
hearts".

Hans
Leber ..." ... after
4♠
the program sees the additionallength
in both hearts and diamonds, and then prefers the majorover
the minor without "thinking", i.e.,
purely rule based.I would
expect the program to have made a simulation,but
it did not, because 5♦
did not come into the picture,
which
I consider an error.If
it had run a simulation (I started one manually in the situation),it
would have selected 5♦.So
5♥
is mainly an error which turned out lucky.
Over
South's 5♦
North would pass if East and West pass, but
run to 5H if 5D is doubled.)"

It
is quite interesting to see how the developers can explore their robots'
'thinking' process!

Board
10 of the final round robin started the same way at all six tables, with East dealer, the bidding
started 1♥-
3 ♠ -
Pass - Pass. At five of the six tables East reopened with a Dbl.

Dealer: East
Vul: Both

♠ 8 6♥ A 9 7♦ Q J 5 3
♣ 9 4 3 2

♠ Q 9 2♥ 10 6♦ 8 6 4 2
♣ K Q 10 8

N

W

E

S

♠ K♥ K Q 8 4 3♦ A 10 9
♣ A J 6 5

♠ A J
10 7 5 4 3♥ J 5 2♦ K 7
♣ 7

West

North

East

South

Micro Bridge

Jack

Micro Bridge

Jack

1♥

3♠

Pass

Pass

Dbl

Pass

3 NT

Pass

Pass

Pass

Opening lead ♠8,
making E/W +600

In one match Micro Bridge (West) bid 3NT, as shown above, and could not
be stopped from making game, while at the other table, Jack (West) bid 4♥and went down 3 for
-300 and 11 IMPs to Micro Bridge.In
another match Shark Bridge (West) bid and made 4♣ for +130 while at the other table Q-Plus Bridge (West)
passed.In 3♠x
Shark Bridge played correctly by setting up a diamond trick
for a heart discard before playing trumps and was +730 (only double dummy
defense can beat 3♠) and
IMPs.In the final match WBridge5
(East) doubled and WBridge5 (West) passed.After
a heart lead, East cashed the club ace and the diamond ace on which Bridge Baron
correctly unblocked the king (not needed in this particular layout) and was
+730.At the other table, Bridge
Baron did not balance with a double, and WBridge5 went down one in 3♠ when
declarer played on trumps before diamonds. 13 IMPs to Bridge Baron.

A good save on
board 15 of the final 16 boards from the last round robin was found three times.In one match Jack picked up 11 IMPs against Micro Bridge.

Dealer: South
Vul: N/S

♠ A J♥ —♦ K Q 9 7
♣ A K Q 10 9 7 3

♠ Q 9 8
5♥6
5 4 3♦ J 6 3
♣ 8

N

W

E

S

♠ K 6 3
2♥ A Q J 10 9 8♦ 8 5 4
♣ —

♠ 10 7
4♥ K 2♦ A 10 2
♣ J 6 5 4 2

West

North

East

South

Jack

Micro Bridge

Jack

Micro Bridge

Pass

Pass

2 ♣

3 ♥

Dbl

4 ♥

4 NT

Pass

5 ♣

Pass

6 ♣

6 ♥

Pass

Pass

Dbl

Pass

Pass

Pass

Opening lead ♠4,
down 3, E/W -800

West

North

East

South

Micro Bridge

Jack

Micro Bridge

Jack

Pass

Pass

2 ♣

3 ♥

Dbl

4 ♥

4 NT

Pass

5 ♣

5 ♥

6 ♣

Pass

Pass

Pass

Making six, N/S +1370

11
IMPs to Jack

Wbridge5 found the save against
Bridge Baron for 17 IMPs (6♥ was not doubled for -200).Q-Plus Bridge gained 13 IMPs against Shark Bridge when it was allowed to
play 5♥x for -500, and made +1390 at the
other table on the ♥A lead.

For a comparison to the human
play, two 16-board sessions were taken from the championship round robin play
(round robin sessions 1 and 14), and used in the final 16-board session of the 2nd
and 3rd round robin.One
can compare the robot results to the human results as all the robot play records
are shown and the links to the human records are given at the official site, www.computerbridge.com

Round 14 of the
human round robin was used in the third round of the robot round robin.On board 12, 7♥was the final contract at three of the six robot tables and 6♥
was the contract at the other three tables.

In one match Jack picked up 13 IMPs against Shark Bridge.

Dealer: West
Vul: N/S

♠ A 8 5
3♥ A K J 5 2♦ A
♣ A J 4

♠ 10 9
6 2♥ 7♦ K Q J 10 7 6
♣ 6 5

N

W

E

S

♠ Q J 7
4♥ 3♦ 9 5 4 2
♣ 10 8 7 3

♠ K♥ Q 10 9 8 6 4♦ 8 3
♣ K Q 9 2

West

North

East

South

Shark Bridge

Jack

Shark Bridge

Jack

2 ♦

Dbl

4 ♦

4 ♥

5 ♦

7 ♥

Pass

Pass

Pass

West

North

East

South

Jack

Shark Bridge

Jack

Shark Bridge

3 ♦

Dbl

Pass

4 ♥

Pass

5 ♥

Pass

6 ♥

Pass

Pass

Pass

13 IMPs to Jack

In another match Bridge Baron
picked up 13 IMPs against Micro Bridge.

West

North

East

South

Baron Baron

Micro Bridge

Baron Baron

Micro Bridge

3 ♦

Dbl

5 ♦

5 ♥

Pass

6 ♥

Pass

Pass

Pass

West

North

East

South

Micro Bridge

Baron Baron

Micro Bridge

Baron Baron

Pass

2 ♣1

Pass

2 ♥

3 ♦

4 ♥

Pass

4 NT

Pass

5 ♥2

Pass

5 NT

Pass

6 ♣3

Pass

7 ♥

Pass

Pass

Pass

1 2NTor game force; 22
or 5 key cards; 3 no kings

13 IMPs to Bridge Baron

In the other match WBridge5 picked
up 13 IMPs against Q-Plus Bridge.

West

North

East

South

Q-Plus Bridge

WBridge5

Q-Plus Bridge

WBridge5

Pass

2 ♦1

Pass

2 NT2

Pass

3 ♥

Pass

4 NT

Pass

5 NT3

Pass

7 ♥

Pass

Pass

Pass

1 game force; 2 no ace,
7+ hcp; 3 5 key cards

West

North

East

South

WBridge5

Q-Plus Bridge

WBridge5

Q-Plus
Bridges

Pass

2 ♣1

Pass

2 ♥

Pass

3 ♥

Pass

3 ♠2

Pass

4 NT

Pass

5 ♣3

Pass

6 ♥

Pass

Pass

Pass

1
2NTor
game force; 2control;
30
or 3 key cards

13
IMPs to WBridge5

In
human competition, the deal was played at 22 tables in each category.7♥was reached 9 times
in the Bermuda Bowl, 9 times in the Venice Cup (played once in 4♥), and 9 times in the d'Orsi
Senior Trophy (played once in 5♥).So the robots' percentage was slightly better than in the human
competition.

Board 15 of the round produced a
large swing on an opening lead against 6♦.

In
one match, both Q-Plus Bridge and WBridge5 bid and made 6♦.

Dealer: South
Vul: N/S

♠ A J 4♥ A 4♦ A Q 10 9 8 5 4
♣ 2

♠ 10 9
7 2♥ Q J 8 2♦ J 7 6
♣ 10 7

N

W

E

S

♠ 8 6 5♥ K 7 6 5 3♦ —
♣ A Q 6 5 4

♠ K Q 3♥ 10 9♦ K 3 2
♣ K J 9 8 3

West

North

East

South

Q-Plus Bridge

WBridge5

Q-Plus Bridge

WBridge5

1 ♣

Pass

2 ♦

Pass

2 NT

Pass

4 ♦

Pass

4 ♠

Pass

4 NT

Pass

5 ♦1

Pass

6 ♦

Pass

Pass

Pass

1 one key cardopening lead, ♠8, making 6, N/S +1370

West

North

East

South

WBridge5

Q-Plus Bridge

WBridge5

Q-Plus Bridge

1 ♣

Pass

2 ♦

Pass

3 ♦

Pass

4 ♣1

Pass

4 ♠2

Pass

4 NT

Pass

5 ♦3

Pass

6 ♦

Pass

Pass

Pass

opening
lead, ♣ A, making 6, N/S +1370

The other time 6♦was bid.

West

North

East

South

Shark Bridge

Jack

Shark Bridge

Jack

1 ♣

Pass

1 ♦

1 ♥

Pass

Pass

2 ♥

Pass

3 ♣

Pass

4 NT

Pass

5 ♣1

Pass

5 ♦

Pass

5 ♥2

Pass

6 ♦

Pass

Pass

Pass

1 one
key card, 2 not the diamond queen… at least N/S are on the same
wave length….can't play in 5♦?

opening lead, ♣ A, making 6, N/S +1370

At
the other table Shark Bridge made +660 in 3NT. 12 IMPs to Jack

At
the final match, the contracts were 3NT, +660 and 5♦,
+620. Bridge Baron picking up 1 IMP against Micro Bridge.

In the human championships, 6♦was reached at many tables, and
for the big clubbers with South as declarer.When South was declarer, West led a heart more often than not, but with
North as declarer, the opposite was true.The
human play (except in Daily Bulletin articles) is not revealed, so the opening
lead cannot be analyzed. In 6♦
from the North side, the human defense got it right some times (25%), but the
robots were 0 for 3.

The final KO between Jack and WBridge5 saw many swing
and potential swing boards.

An excellent grand was bid and made at both tables on
board 11 of the 3rd quarter.

Dealer: South
Vul: None

♠ 3♥ 8 6 4♦ 10 8 6 4
♣ Q 9 6 5 2

♠ K 7 5
2♥ A♦ A K Q 7 2
♣ A 10 8

N

W

E

S

♠ A Q
10 9 6♥ Q J 10 9 5♦ 5 3
♣ K

♠ J 8 4♥ K 7 3 2♦ J 9
♣ J 7 4 3

West

North

East

South

WBridge5

Jack

WBridge5

Jack

Pass

1 ♦

Pass

1 ♠

Pass

4 ♥1

Pass

4 NT

Pass

5 ♦2

Pass

5 NT

Pass

6 ♦3

Pass

7 ♠

Pass

Pass

Pass

1singelton
or void; 2 1 or 4 key cards; 3 one king

West

North

East

South

Jack

WBridge5

Jack

WBridge5

Pass

1 ♦

Pass

1 ♠

Pass

4 NT

Pass

5 ♣ 1

Pass

5 ♦

Pass

5 NT 2

Pass

7 ♠

Pass

Pass

Pass

1one
key card; 2 trump queen and club king (one king, not in hearts)

Made 7 at both tables, E/W
+1510, no swing

The last board of the match shows an
interesting inference that humans sometimes get right and sometimes get wrong
but robots always get wrong.

The play often
depends on declarer's estimate of the level of an opponent's play. Robots
don't make such a judgment.

The
play comes down to finding the ♣10. The
holdings that matter to declarer are West holding ♣ K, ♣ K 10, K x and K x x x. With
♣ K x x, West will always duck the king and defeat the game.
With K x x x, West will never cover
with the king as the 10 will
show up. With K 10, West will always
cover. Now with K x, do you cover or
not? If it is known that West always
covers with K x declarer will always get K x x x right (when the king doesn't
appear play for the K x x x as opposed to K x); have a guess for K 10, singleton
K and K x
when it does appear, with the finesse of the 10 approximately four times as likely
to win as the drop
of the 10 from K 10. If it is known that West
never covers with K x then declarer will always get K 10 right and singleton K
wrong, and have a guess for K x and K x x x when the king doesn't
appear. Of course on any given hand
declarer might be able to determine the count on the suit in question, as on
this hand, after playing the side suits, west cannot have 4 clubs, so declarer
will play for K x. A cat and mouse game…or
game theory.If defender assumes,
from K x, that if covering with the king, the declarer will almost always
finesse for the 10, then defender will never cover from K x. If
declarer knows this is defender's thinking, then declarer will always get K 10
right and singleton king wrong! A
matter of game theory (judging the probability of your opponent's play from
certain holdings) which the robots don't do! The
robots will always finesse for the 10 when the king is played and apparently
(most robots) play
the K from K x. In
human play, with two known experts against each other, duck from K x most of the
time (Edgar Kaplan would give the percentage quite accurately (80% of the
time?)...as he did in his famous "The Deep Nine" article (The Bridge
World, October 1973).

A slightly against the odds vulnerable
slam by Jack produced a 13 IMP gain on Board 3 of the second quarter.Down one would have given WBridge5 13 IMPs and the crown!

Board 3 of the 2nd
quarter may have determined the winner.

Dealer: South
Vul: E/W

♠ 10 5 3♥ J 10♦9 7 3 2
♣ K 9 8 5

♠ A 8 7 4 2♥A Q 6♦J 5
♣ J 10 6

N

W

E

S

♠ K Q 6♥5 3 2♦A K 10 6
♣ A Q 2

♠ J 9♥ K 9 8 7 4♦Q 8 4
♣ 7 4 3

West

North

East

South

WBridge5

Jack

WBridge5

Jack

Pass

1 ♠

Pass

2 ♦

Pass

2 NT

Pass

3 ♠

Pass

4 ♠

Pass

Pass

Pass

Opening
lead ♣5,
making 6: E/W +680

West

North

East

South

Jack

WBridge5

Jack

WBridge5

Pass

1 ♠

Pass

2 ♦

Pass

2 NT

Pass

4 ♣

Pass

4 ♠

Pass

4 NT

Pass

5 ♥1

Pass

5 NT

Pass

6 ♣

Pass

6 ♠

Pass

Pass

Pass

12 of 5 key cards
without trump queen; 2 no kings

The probability of making 6♠ is
41.4% (56% of the 67.8% of the times trumps are 3-2 [whenever the club king is
onside, with 5 spades, 3 diamonds, 3 clubs and 1 heart; and 1/8th the time the
club king is offside], plus 12.5% of the 28.3% of
the timestrumps
are 4-1; plus none of the 3.9% of the times trumps are 5-0.). The
so called "rub of the green" in bridge! A
long match can be decided by one slightly lucky deal. Of
course, the luck tends to balance out and without a complete analysis it
can't be determined which side had the better of it.

In
summary...At
table 1, declarer played a heart to the ace at trick 2. When South
followed, declarer was assured of 12 tricks. A finesse at trick two would
guarantee the contract against a four card heart holding by North, barring an
unlikely ruff at trick three. At table two, Wbridge5 would be assured of
the contract with a heart finesse at trick
two. Instead declarer took a spade finesse at trick two and went down when
the hearts did not come home.

For
complete results go to www.computerbridge.comYou will find the 17 year history of the event, along with many
publications and descriptions of computer play.This year’s results also offer an opportunity to compare robot play
against human play, with two sets of 16 boards to compare.The complete robot play of the two sets are shown.The complete play of the final KO is also shown along with some
highlights.